1. Field of the Invention
The present invention relates generally to the compromise or deterioration of roofing membrane materials by the condensate from air conditioning systems that are mounted on or above the roofs of commercial buildings that are finished with a roofing membrane that is slightly inclined or contoured, so as to direct water to drain openings in the roof and into drain conduits. More particularly, the present invention concerns the provision of a roof mounted drain system for collecting air conditioning condensate from roof-mounted air-conditioning units and conducting the condensate to a disposal drain and simultaneously isolating the roof membrane from contact by the air conditioning condensate. Even more specifically, the present invention concerns structure and materials for creating a plurality of nondestructive water conducting paths over the surface of a roofing system, that will direct discharged air conditioning condensate from roof mounted air conditioning units to one or more in-roof drains or gutters for disposal and will serve to isolate the roof membrane from the condensate.
2. Description of the Prior Art
Roofing membrane deterioration is typically caused by the presence of persistent air conditioning (“a/c”) condensation in localized areas on a roof surface, regardless of the roof surface membrane or construction. It has been determined through tests that a/c condensation moisture is laden with various chemical constituents and heavy metal concentration. Moreover, as water evaporation occurs and a/c condensation continues to be added onto the roofing membrane, the concentration of chemicals and heavy metals will continuously increase thus increasing the detrimental effect of these materials to the roofing membrane. Particularly, a/c condensation fluids attack the roof membrane in areas where it flows and in collection areas where it tends to collect in pools on the roof membrane surface. It has been found that summer heat will actually turn the water flows and pools into boiling water which will literally oxidize the roofing membrane. Extreme cold will freeze these water flows and pools causing fissures in the roof membrane surface. This problem is well documented by the National Roofing Contractors Association, manufacturers of roofing materials, and other roofing industry experts. Present methods of removing the a/c condensation from the roof surface are not effective. The following is a brief description of the most commonly utilized methods for a/c condensation removal from roofing systems.
PVC or Metal Piping
The most common method utilized for the collecting and removal of a/c condensation from a roofing system is to connect a form of piping to the a/c unit and to run the piping from the unit to a suitable point of drainage. Typically, condensate collected in the condensate collection pan of a/c unit will exit the collection pan at a discharge opening and will flow into a drain line through a water trap, also referred to as a “P-trap”. The P-trap is a U-shaped conduit section maintaining a water seal between the collection pan and the drain line which functions to isolate air within the drain line from the interior of the a/c unit. Debris and algae will build up or become deposited within the P-trap as well as the drain line and will block the flow of condensate discharge from the collection pan. When a/c condensate drainage piping is utilized, the different types of drainage piping will vary from polyvinyl chloride (PVC) piping, galvanized steel piping, copper piping, and even black iron gas line piping. It has been found with condensate drainage piping that the piping systems quickly become clogged with debris and algae that is present within the drainage system, especially when the a/c unit is situated in a humid environment. It is not unusual for P-traps and drain lines to require service three to four times per year to remove algae and debris blockage Obviously, when a/c drain conduits become clogged to the point that condensate water cannot flow freely there-through, the condensate will build up within the condensate collection pan until it flows into air flow ductwork and then seeks its way into the building. Service personnel are then called on an emergency basis to repair the roof sufficiently prevent leakage of water into the building. At times condensate will build up within the a/c unit until it begins to leak around the edges of the collection pan, in which case it will flow onto the roofing membrane, causing deterioration of the roof membrane as mentioned herein. If the a/c unit structure is partially rusted away adjacent the perimeter of the condensate collection pan, which is often the case, significant leakage of condensate onto the roofing membrane will occur. The condensate will then flow along the roof membrane, following the natural slope of the roof membrane and will develop one or more pools of condensate liquid on the roof surface. This condensate liquid, because it is laden with chemicals and heavy metals as mention above, will begin to degrade the roof membrane. As typically occurs in roofing systems, having condensate drain conduits, because of traffic, age, and constant clogging problems requiring significant maintenance effort and expense, personnel having the responsibility for building maintenance will eventually disconnect the condensate drainage pipes from the air conditioning units. This of course, will cause the a/c condensate to be discharged directly from the collection pan through the drain opening and onto the roof membrane surface. When the drain piping is disconnected in this manner, it is done with the knowledge that deterioration of the roofing membrane by the discharged a/c condensate will eventually result and that, as a consequence, roofing repair will be necessitated in a relatively short period of time. The eventual result is that the disconnected a/c drainage pipes will end up as debris that is present on the roof surface. This disconnected piping debris obviously presents a hazard to workers engaged in roofing maintenance and repair and can be a cause of damage to the roofing membrane.
Internal Piping
While commercial buildings can be provided with internal a/c drain piping systems that extend throughout the building structure to conventional building drain lines, this internal piping method is seldom used because it is expensive and requires frequent maintenance. Internal condensate drainage piping is a piping system that is connected with the condensate discharge drains of the various a/c units and extends to plumbing drain lines within the confines of the building structure. Debris collected by the condensate of the a/c units will flow along with the condensate into the drain lines and in time will clog the lines. The algae that builds up in all a/c drain lines also causes clogging of the lines. In a relatively short time the drain lines will be sufficiently blocked that flow of condensate drainage will be blocked. This will cause the a/c condensate to enter duct-work and flow into the building structure as mentioned above. These systems are virtually always abandoned due to clogging because the drain lines, being located within the building structure are difficult to access and service or repair.
Surface Drainage
Even though the presence of a/c condensate on a roof membrane is known to cause damage to the roofing system, surface drainage is the method that is most often employed for condensate drainage. Since drainage systems composed of metal or PVC pipe will become clogged and inoperative in a short period of time and are also expensive to install and maintain, it has been found most practical to allow roof surface drainage to occur, knowing that the roofing system will require repair at more frequent intervals. In this case, persistent a/c condensation fluids are allowed to collect in certain areas on the roof membrane surface, causing extensive and accelerated roof membrane deterioration. It is desirable therefore to provide an a/c condensate drainage system for flat roofed building structures which will not be subject to frequent blockage by debris, algae and the like and yet will continuously exclude a/c condensate drainage fluid from the roof membrane surface. It is also desirable to provide flat roofing systems of building structures with a/c condensate drain systems that will efficiently drain a/c condensate fluid along the roof surface to appropriate roof drains for disposal without permitting the a/c condensate to collect on the roof membrane.
Types of Roofing Systems
The following types of roofing systems with roof mounted a/c units are specifically noted as roofing systems that would benefit from installation of an air conditioning condensation drainage system according to the present invention.
Single Ply Roofing Systems
This type of roofing system includes all single ply systems such as ethylene propylene diene monomer or ethylene propylene diene terpolymer (EPDM), polyvinyl chloride (PVC), chlorosulfonated polyethylene (CSPE), also referred to by its registered trademark HYPALON®, thermoplastic olefin (TPO), and/or other types of single ply roofing membranes of chemically or heat welded seam systems.
Modified Bitumen Roofing Systems
Modified bitumen roofing systems include all types of roofing systems that have a styrene butadiene styrene (SBS) or atactic polypropylene (APP) modified bitumen surface layer.
Built-Up Roofing Systems
Built-up roofing (BUR) systems include all types of coal tar and asphalt built-up roofing systems that utilize felts or other fabrics as interply sheets that represent integral components of construction.
Metal Roofing Systems
The term “metal roofing systems” is intended to encompass standing seam metal roofing, corrugated metal roofing and any other metal roofing that is applied in panels and having leakage preventing treatment at any panel joints that exist. The term “metal roofing systems” is also intended to encompass metal roofing installations having a metal roofing membrane and having ridge members which are attached to metal roofing by means of cement, bonding material or the like and which simulate standing seam metal roofing.
Other Roofing Systems
The term “other roofing systems” is intended to encompass all other types of roofing systems that have a smooth surface of material or materials being exposed to weather and which define a roofing membrane that excludes water from the interior of a building structure.